Will proposed to Nico by doing the traditional getting down on one knee, speech thing, then instead of a ring he pulled out and apple and threw it at Nico yelling "Think fast!" Nico was confused at first until Piper explained that in Ancient Greece if you threw and apple at someone and they caught it, it was a marriage proposal. Percy and Annabeth started blushing while Grover started laughing (or bleating) at them. When Jason asked why they were blushing Percy said that on one of their fist quests when they were twelve, they were bored and started playing hackey sack with an apple, so they were technically engaged since they were 12 without the realizing it. Everyone started laughing about that.